Project Summary/Abstract Tourette's syndrome (TS) is a childhood-onset tic disorders that is associated with a spectrum of co-occurring neuropsychiatric problems (particularly ADHD and OCD) and that has been found to be much more common than once thought. Taken together, the features of TS can be disabling and have significant impacts on individuals with the condition, their families and their communities. Systematic collection of accurate data regarding these impacts is a prerequisite for the development of interventions and for changes in health care policies and services aimed at reducing the negative consequences of TS. In keeping with the RFA, we propose to recruit 100 youth probands with TS (and their parents and siblings) and 100 matched healthy control youth (and their parents and siblings). The subjects will be administered a standardized battery of validated self-report, interview-based and teacher-report instruments in order to: 1) obtain demographic information, 2) define the tic disorder and its severity, 3) define the presence and severity of co-occurring neuropsychiatric conditions, 4) assess the impacts on individuals with TS (quality of life [QoL], and overall, school and social functioning), 5) assess the impacts on families (parent QoL, family functioning, socioeconomic, sibling QoL, and overall, school and social functioning), and 6) assess the impacts on the community (estimated costs of additional educational, social, health care and economic resources). The impacts of TS will be assessed by comparing TS and control subjects/families. These groups will also be compared to national survey data. In order to identify the best targets for intervention, we will use regression analysis to determine which demographic and clinical features and measured impacts most closely correlate with (predict) measured QoL in individuals with TS and their families (parents).